Hi all, check engine light is on with my 1990 b2600. Even when I ground the single wire from the green plug the light does not flash. There was no change in engine performance so I am wondering if a wire in the mil system has grounded thus illuminating the bulb. This would explain why it wont flash. Any thoughts?

 

Forget about trying to pull any codes.......if the truck engine is running fine, just reset the MIL by swapping the wire connectors under the Driver's side dash per the instructions from the Mazda Factory Service Manual that I posted in your other thread. This will turn your MIL light off as it was designed by Mazda to do.

Let us know how it worked.

 

youre advice was spot on, after I replaced the negative battery clamp that was somewhat dissolved.